Processing and characterization of graphene (Gr)-reinforced aluminium alloy 7075 (AA7075) microcomposites and nanocomposites are reported in this work. Composites are fabricated by mechanical alloying process at wet conditions. The bulk composites are prepared by uniaxial die pressing to get higher densification and sintered in an inert atmosphere. Density of the nanocomposites is higher than the microcomposites due to the reduction of grain size by increased milling time. X-ray diffraction (XRD) analysis confirms graphene interaction with the AA7075 matrix lattice spaces. The effective distribution of graphene with aluminium alloy is further confirmed by the Transmission Electron Microscopy (TEM) analysis. The hardness of the composites proportionally increases with the graphene addition owing to grain refinement. Wear morphology is characterized using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Microcomposites reveal abrasive and ploughing wear mechanism of material removal from the surface. Nanocomposites show adhesive wear with delamination and particle pull-out from the material surface.

这项工作报道了石墨烯（Gr）增强铝合金7075（AA7075）微复合材料和纳米复合材料的加工和表征。复合材料是在潮湿条件下通过机械合金化工艺制造的。通过单轴压模制备块状复合材料以获得更高的致密性，并在惰性气氛中烧结。纳米复合材料的密度高于微复合材料，这是由于通过增加研磨时间而减小了晶粒尺寸。X射线衍射（XRD）分析证实了石墨烯与AA7075基质晶格空间的相互作用。石墨烯与铝合金的有效分布进一步由透射电子显微镜（TEM）分析确认。由于晶粒细化，复合材料的硬度与石墨烯的添加成比例地增加。磨损形态是用扫描电子显微镜（SEM）和原子力显微镜（AFM）表征的。微复合材料揭示了从表面去除材料的磨料和耕作磨损机理。纳米复合材料显示出粘合剂磨损，并发生分层和从材料表面脱落的颗粒。